1. Field of the Invention
The present invention relates to a novel silver halide color photographic photosensitive material and a novel method for forming an image by using said photosensitive material.
2. Description of the Related Art
The so-called color negative, which is known in conventional color photography, generally contains a yellow dye image forming layer for recording blue light, a magenta dye image forming layer for recording green light, and a cyan dye image forming layer for recording red light. In the developing process a developing agent is oxidized when silver halide grains containing a latent image are reduced to silver, so that a dye image is formed by a (coupling) reaction between a coupler and the oxidized form of the developing agent. The unreacted silver halide and the developed silver generated are removed through bleaching and fixing processes that follow. Subsequently, color photographic printing paper is optically exposed to light through the dye image of the color negative, and is again subjected to the same developing, bleaching and fixing processes to obtain a color print.
Also known is a method in which, after image information contained in the color negative is optoelectrically read, the image information is processed to produce image information for image recording and for producing color images on other printing materials by using the image information for image recording. In particular, a digital photoprinter, in which the image information is converted into digital signals and a photosensitive material such as color paper is scan-exposed to light modulated in accordance with the signals to obtain a color print, is being developed and an example of the digital photoprinter is described in Japanese Patent Application Laid-Open (JP-A) No. 7-15,593.
Since the above-mentioned methods are based on conventional wet-process development, bleaching and fixing, they are complicated.
In contrast with such methods, simple and rapid processes using heat development are being developed for the processing of silver halide color photosensitive materials. Examples are the Pictrography and Pictrostat products developed by Fuji Photo Film Co., Ltd. An embodiment of the heat development is a process in which a photosensitive material is processed in the presence of a small amount of water and a base and/or a base precursor; For example, Japanese Patent Application Publication (JP-B) No. 2-51,494.
Many of these photosensitive materials for use in heat development were photosensitive materials for print. But the recent JP-A No. 9-10,506 discloses an example in which photosensitive material used in photographing is heat developed in the presence of a small amount of water and a base and/or a base precursor. Then the image obtained is read, image-processed and outputted to a printing material. However, since the silver halide emulsion used in this example was not highly sensitive, the sensitivity/RMS granularity was not satisfactory. That is, the problem was that the print obtained by reading and image-processing an image obtained was inferior to a conventional photograph in sensitivity/RMS granularity.
Tabular silver halide grains are known as a highly sensitive silver halide. This is because the tabular silver halide grains have a larger surface area/volume ratio, and therefore a highly sensitive silver halide emulsion can be prepared by the adsorption of a large amount of sensitizing dye onto the grains. The ratio of the major plane to the thickness of the tabular silver halide grain is called the aspect ratio. The larger this aspect ratio is, the larger the surface area/volume ratio of the grain is.
However, the problem was that spotted color unevenness was generated when a photosensitive material was processed by a simple and rapid heat development in the presence of a small amount of water and a base and/or a base precursor even when the photosensitive material comprises silver halide grains having a high aspect ratio used in silver halide photosensitive materials for use in conventional photography. As a result, a highly sensitive silver halide having a high sensitivity/RMS granularity could not be used.